Now there's a question, isn't there?

The answer, of course, depends on who you ask.

In this recent thread I give my best summary of the current historiography of the fall of the western Roman Empire, and there's also a discussion between u/shlin28 and I on this very question. (Part of that discussion is in a linked Sunday Digest thread)

More answers and discussion is of course always welcome, but that should hopefully provide a nice starting point.